Emily Ridley has been a Captain in the Salvation Army for over 30 years. She is asked to retire and she refuses, so they post her to quiet, uneventful towns in Yorkshire where she won't bother anyone, or so they thought.
Food poisoned by a ham sandwich from the mobile canteen, Emily is out of commission. Sister Alice and Dorothy run the show without her. The results are grim, as the two sisters are too easy on the sinners.